Threshold assemblies are known in the prior art which are received between the bottom of a door and the floor and which have vertically adjustable weather seals to account for misdimensioned doors or variations due to weather or use. However, there are numerous disadvantages in these prior art thresholds. For example, in U.S. Pat. No. 2,839,796 issued to Quoss on June 24, 1958, the weather seal is received in a recess in the threshold and is caused to bulge or arch upwardly by selective positioning an edge piece which is moved towards or away from the seal. A plurality of elongated slots formed in the edge piece receive a plurality of screws to adjustably position the edge piece, and therefore vary the vertical height of the seal. However, such an adjustable feature is not very firm and secure because the edge piece is exposed to foot contact and either a downward pressure on the seal, such as that caused by someone stepping on the seal, or kicking the edge piece as in normal use would tend to loosen the edge piece and therefore relax the seal.
In U.S. Pat. No. 3,900,967 issued to Bursk et al on Aug. 26, 1975, a threshold is disclosed in which there is an elastomeric seal having vertical adjustability. However, the support for this seal in the vertical direction relies on frictional engagement and does not appear very strong, so that stepping on the seal would tend to reduce the vertical height thereof, thereby diminishing its sealing effectiveness and negating any prior upward adjustment.
In U.S. Pat. No. 4,003,162, issued on Jan. 18, 1977 to Britt, the threshold is formed from two separate assemblies which have the elastomeric seal therebetween, the vertical height of the seal being variable upon relative movement of these two assemblies towards and away from each other. Thus, in order to vary the height of the seal, the entire threshold width must be varied.
In addition, many of these prior art devices, are extremely complicated, requiring costly materials and complex manufacturing procedures.